(1) Field of the Invention
The present invention relates to an assembly of pitot tubes for use in turbulence measurements and more particularly to a multi-pitot tube assembly having a plurality of independent pitot tubes sealed in a common plug. The pitot tubes are pre-formed into a desired shape, nested together and passed through an alignment disk into separate spread holes in the common plug. The pitot tubes, alignment disk and plug are inserted into a mold and polyurethane is injected to seal the individual tubes. The polyurethane also forms a fin structure from which the pitot tubes extend for insertion into the flow stream. The plug is shaped to conform to the test platform to which the assembly is attached.
(2) Description of the Prior Art
The use of pitot tubes to measure static and dynamic pressures in a fluid medium is well known. Assemblies having multiple pitot tubes have been used in studying the dynamics of a wake caused by an object moving through a fluid such as water. In order to obtain a dynamic profile of the wake, the pitot tubes in these assemblies are normally stacked in a row extending perpendicularly from the moving object, with the row bending 90.degree. into the wake. A fin structure is provided to minimize turbulence caused by the assembly. Such prior art assemblies are constructed by hand. The fin structure has a hollowed out cavity and is supported by a base attached to the object under study. Multiple pitot tubes are hand bent to fit around the fin structure, into the cavity, through the base and into the object. The cavity is sealed with an epoxy-type filler, which after hardening is sanded to match the shape of the fin. A half round fairing is attached to the fin structure using the same epoxy-type filler. Such prior art assemblies have several disadvantages. First, hand bending of the pitot tubes, sanding of the epoxy-type filler and attachment of the fairing are labor intensive operations making such assemblies expensive. Second, the attachment of the base to the object and the placement of the pitot tubes around the fin structure cause significant turbulence in the flow being measured. Thirdly, accomplishing a water-tight seal around the cavity and the pitot tubes, and between the base and the object is extremely difficult. Finally, such prior art assemblies suffer wide variations in the configuration of pitot tubes and fin shape due to hand assembly. These variations result in performance characteristics varying from one assembly to the next.